<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>公共头</title>
</head>
<body>
<nav th:fragment="common_nav">
    <h2>欢迎您:[[${session.users.getUsername()}]]
     <a href="logout" th:href="@{/user/logout}">退出登录</a>
    </h2>
</nav>
</body>
</html>